Investigation of p-type behavior in Ag-doped ZnO thin films by E-beam evaporation

Ag-doped ZnO (ZnO:Ag) thin films were grown on glass substrates by E-beam evaporation technique. The structural, electrical and optical properties of the. lms were investigated as a function of annealing temperature. The. lms were subjected to post annealing at different temperatures in the range of 350 650 degrees C in an air ambient. All the as grown and annealed. lms at temperature of 350 degrees C showed p-type conduction. The. lms lost p-type conduction after post annealing treatment temperature of above 350 degrees C, suggesting a narrow post annealing temperature window for the fabrication of p-type ZnO: Ag. lms. ZnO: Ag film annealed at 350 degrees C revealed lowest resistivity of 7.25 x 10(2) Omega cm with hole concentration and mobility of 5.09 x 10(19) cm(3) and 1.69 cm(2)/Vs, respectively. Observation of a free-to-neutral-acceptor (e, A degrees) and donor -acceptor-pair (DAP) emissions in the low temperature photoluminescence measurement confirms p-type conduction in the ZnO: Ag. lms. (C) 2008 Elsevier B. V. All rights reserved.